WALTHAM — The Celtics' summer league team was nearly two hours into the first of two workouts Tuesday when several of the players cooled down with some additional shots.

Second-year point guard Phil Pressey marched over to the arc at one of the far baskets and began firing up 3-pointers. Rookie point guard Marcus Smart lined up right behind him as the pair traded off with each miss.

The long-distance shot has been a weakness for both throughout their respective careers and something they both know they’ll have to improve upon as professional players.

While they could easily see each other as rivals for minutes — and in Pressey’s case, with an non-guaranteed contract, perhaps even a roster spot — the two young backcourt mates immediately put that aside in search of a greater goal.

"Competition just makes your team better," said Pressey, "when you’ve got guys who are all at the same level trying to reach the same things. But we’re trying to win. Competition is no problem for me.

"I’m just trying to get better. Marcus, myself, (first-round pick) James Young — it doesn’t matter who’s on the court. We’re all basketball players and the most important thing is winning. I just have to keep proving myself. There’s been a chip on my shoulder since Day 1 and that’s not going to change."

Pressey, who went undrafted out of Missouri last year before making the team and starting 11 games — where the team went 6-5 with him in the first five — admitted he had a momentary pause when the Celtics chose Smart at No. 6 in last Thursday’s draft. But he said the feeling quickly passed as he focused on what Smart could do to help the team do what it did far too little of in going 25-57 last year.

"My whole life my biggest thing is winning," Pressey said. "I’ve never been a loser. I’m just trying to get back to my winning ways.

"Whenever you get somebody (drafted) at your position, you’re like: ‘What’s going on?’ But, in my eyes, it’s a competition. The more you compete, the more your team gets better. Every year someone’s going to come in. Your position is someone else’s position."

Celtics president of basketball operations Danny Ainge said Monday that he could see Smart and Pressey sharing time on the court this season in a four-guard rotation that includes four-time All-Star Rajon Rondo and restricted free agent Avery Bradley. He added that Celtics coach Brad Stevens may even be able to use some three-guard lineups to get a trio of the players on the court at the same time.

Page 2 of 2 - But the one thing all four guards have in common is that none of them has exactly been known as a dead-eye shooter.

"I’ve just got to take better shots," said Smart, who shot 42.3 percent overall and 29.9 percent from behind the arc in averaging 18.0 points a game for Oklahoma State last season. "I took a lot of tough shots in college. I want to take easier shots, and my percentage will go up a lot more."

Smart admitted he forced a lot of shots while trying to carry the load for the Cowboys, which he knows he won’t be asked to do in his rookie year in Boston.

"Not at all mechanically," he said of any changes in his shot. "They want to make sure I’m getting my shots up and taking the right shots. It’s about repetition, muscle memory."

Pressey shot just 30.8 percent from the floor last year and 26.4 percent on 3-pointers while averaging 2.8 points per game in 15:05 a night.

"It’s just being in the gym two or three times a day getting up as many shots as possible," Pressey said of improving those numbers. "I am dedicating this whole summer to the game of basketball. And hopefully I can really prove myself.

"It’s confidence and just more shooting. In college and high school you’ve got school, and you’ve got other things to do. But in the NBA you’ve just got basketball. There’s no reason why you can’t get in the gym and get better."

That’s what the two young guards did together Tuesday as they turned from potential rivals to teammates over the course of one two-hour workout.

"Being a Dallas neighbor of me, we’ve known each other from back home," Smart said. "Obviously, he’s not that much older than me. He hasn’t been playing that long.

"But he knows some things that I don’t. And that’s a good thing."

Scott Souza can be reached at 781-398-8006 or ssouza@wickedlocal.com. Follow him on Twitter @scott_souza.